1. Field of the Invention
This invention relates to link parameters in a communication environment involving two or more transmitting and receiving devices.
2. Related Art
Link parameters are used to establish the operational parameters for a communications session between two or more devices. For example, the Link Control Protocol (LCP) establishes, configures, and tests data-link Internet connections. Before establishing communications over a point-to-point link (PPP), each end of the PPP link must send out LCP packets (handshaking). The LCP packet accepts or rejects the identity of its linked peer, agrees upon packet size limits, and looks for common misconfiguration errors. Essentially, the LCP packet checks the telephone line connection to see whether the connection is good enough to sustain data transmission at the intended rate. Generally, link parameters apply equally to wired and wireless networks.
Currently, link parameters at all layers of the protocol stack need to be synchronized between a transmitter and a receiver for communications to take place. When link parameters are static, they can be set at the time that the link is initialized and remain unchanged for the entire communication session. When link parameters are dynamic, then current protocols such as the LCP cited above, require two-way handshaking between the transmitter and the receiver in order to change the link parameters.
Two-way handshaking involves a message from the first station to the second station requesting the change in parameters, followed by, a response from the second station back to the first station agreeing to the change. It is only after the second message is reliably received at the first station, that the new link parameters can take effect.
While this current state of the art accomplishes the task of allowing link parameters to be changed, it suffers from several drawbacks. First, it consumes additional valuable link bandwidth and slows communication, as additional communication is required to coordinate link parameters between two stations. Second, if the link is highly dynamic the situation may arise that the link parameters have to change faster than the time required to do a handshaking procedure. In this case, the handshaking protocol would not work and data could be lost.
Accordingly, it would be advantageous to provide a technique that allows link parameters to be changed quickly and efficiently and avoid the use of two-way handshaking. This is achieved in an embodiment of the invention that is not subject to the drawbacks of the related art.
The invention provides a method and system for dynamically controlling link parameters during communication between one or more receiver/transmitters. Transmissions are sent as frames from a Base Station Controller to one or more Customer Premises Equipment. Together with a payload, each frame contains a special control message that pre-announces to both the transmitter and receiver the link parameters to be used until changed. The receiving Customer Premises Equipment processes the link parameters and returns a payload of its own within the same frame. With this dynamic approach, link parameters may be changed as often as each frame.